Satsanga, Satsangam, Satsang in Indian religions is being in the company of the truth or the good, by sitting together with a guru or a group of spiritual students.
sat = true; see also Sacca and Satyagraha
sanga = company
According to Liselotte Frisk, satsang is:.
... a traditional activity in the Indian spiritual context, meaning "being with good/righteous companions." Satsang is a sitting together with an enlightened person who usually gives a short speech and then answers questions.
This typically involves listening to or reading scriptures, reflecting on, discussing and assimilating their meaning, meditating on the source of these words, and bringing their meaning into one’s daily life.
According to Krishnamurti, satsang means "association with the good:
Needleman: [...] I was reading a book the other day which spoke of something called "Sat-san".
Krishnamurti: Do you know what it means?
Needleman: Association with the wise.
Krishnamurti: No, with good people.
Needleman: With good people, Ah!
Krishnamurti: Being good you are wise. Not, being wise you are good.
Needleman: I understand that.
Krishnamurti: Because you are good, you are wise.